Gases
Argon gas (Ar) for TIG and MIG welding, heat treatment and laboratory use
Argon is the standard shielding gas for TIG and MIG welding because it is completely inert and heavier than air, so it blankets the weld pool rather than drifting off it. KIGL supplies argon in IS 5760 Grade 3 welding grade at ≥99.99 % and higher purity on request, in cylinders and cascades.
By Mithillessh Garg, Director (Gas Supply)
₹220 – ₹250 per Nm³ Indicative. Your quotation is the figure that counts — price moves with quantity, cylinder size, contract term and delivery.
- IS 5760
- Specification
- ≥99.99 % Ar
- Purity, welding grade
- Peacock blue
- Cylinder colour
- EN ISO 14175
- Shielding gas standard
- UN 1006
- UN number
Why argon is the default shielding gas
Two properties, and both matter.
It is a noble gas — genuinely inert, with no reaction with molten metal at any welding temperature. And it is heavier than air, at about 1.38 times the density, so it settles over the weld pool and stays there instead of drifting away.
Nitrogen is cheaper and unreactive at room temperature, but it dissociates in the arc and can form nitrides that embrittle the weld. Helium works and gives a hotter arc, but costs far more and is lighter than air so it needs higher flow. Argon is the practical answer for most work, which is why it dominates.
KIGL supplies argon to IS 5760 in welding grade at ≥99.99 %, with higher purity on request.
Argon applications in industry
TIG welding
The standard shielding gas across steel, stainless, aluminium and reactive metals.
MIG welding
Pure argon for aluminium; argon-CO₂ or argon-oxygen mixtures for carbon and stainless steel, where a little active gas improves arc stability and penetration.
Root purging
Displacing air from the underside of a weld to prevent oxidation, particularly on stainless steel pipework.
Heat treatment
Annealing, brazing and hot isostatic pressing under a protective atmosphere.
Laboratory use
Carrier gas in gas chromatography, and the plasma source in ICP-MS.
Metal production
Argon stirring and degassing in steel and non-ferrous processing.
Filled industrial gas cylinders, ranked upright in the yard for despatch
Guwahati works · agent network
Getting the shielding right
Most argon-related weld defects are not gas quality problems. They are shielding problems.
More flow is not better shielding
Excessive flow becomes turbulent at the nozzle and actively draws air into the shield. If a weld looks grey or sooty, reduce flow before increasing it.
Draughts destroy shielding
A fan or an open shutter across the work will contaminate the weld regardless of gas purity.
Check the delivery path
A cracked hose, a worn gas lens or a loose fitting lets air in downstream of everything you paid for.
Purge properly at the start of a run and after any cylinder change.
Which argon grade your work needs
| Grade | Typical purity | Used for |
|---|---|---|
| Welding grade | ≥99.95 % | TIG and MIG on steel, stainless and aluminium; general shielding |
| High purity | ≥99.999 % | Instrument carrier gas, heat treatment of reactive metals, laboratory work |
For almost all fabrication, welding grade is the correct answer and the higher grade is money spent on a number. The exceptions are real but narrow: welding titanium and other reactive metals, where even trace oxygen and nitrogen embrittle the weld, and analytical work where the gas is part of the measurement.
The impurity that matters in shielding argon is moisture, not the headline purity. Water in the shield gives porosity in aluminium welds, and it usually arrives from a damp hose or a cylinder left open rather than from the gas. Purge the line before striking an arc.
What argon actually costs you
Argon is the dearest of the common air gases, indicatively ₹220 to ₹250 per Nm³ against ₹32 to ₹40 for oxygen, because it is under 1 % of the atmosphere and separating it takes correspondingly more work. Two things decide your annual bill more than the rate does.
Flow rate. Most shops run far more argon than the job needs. A flow meter set by habit rather than by the torch and joint wastes gas continuously, and excess flow actively harms the weld by drawing air into a turbulent shield.
Purge losses. Gas spent purging lines, backing purges and leaks that nobody has looked for. A soap test across the regulator, hose and torch connections costs nothing and is the usual place a cylinder a month disappears.
Indicative pricing and the six things that move a gas quotation are on the industrial gas prices guide.
Is argon gas flammable?
No. Argon is a noble gas: it does not burn, does not support combustion and does not react with the metal, the arc or the air around it, which is exactly why it is used to shield a weld. The hazard is the opposite one — argon is about 1.38 times as dense as air and displaces oxygen in pits, tanks and trenches without any smell or warning. Treat an argon leak as an asphyxiation risk, never as a fire risk.
Safety
Argon is inert, non-toxic and non-flammable — and an asphyxiant that gives no warning.
Because it is heavier than air, argon collects in pits, trenches, tank bottoms and confined spaces and stays there. This is the specific hazard that kills welders: an argon-filled pit looks exactly like an empty pit. Someone entering loses consciousness within a breath or two, with no smell, no irritation and no sense of breathlessness.
Monitor oxygen before entering any low-lying or confined space where argon has been used. Never rely on ventilation clearing it by itself.
Full detail is in the argon safety data sheet.
Argon cylinder sizes and supply across India
Cylinders and cascades from Guwahati, and through a network of agents, with exchange and refill programmes, and mixtures specified against your material and process rather than sold from a standard list.
Why KIGL
Why buy argon from KIGL
KIGL has filled industrial gas in Assam since 1947, under PESO licence, to the Indian Standards the own people helped draft. Argon is a gas where the grade is decided by the work rather than by the price list. State the parent metal, the thickness and the transfer mode, and KIGL will specify against the weld. Where a cheaper grade will hold it, KIGL says so.
Specification
Argon gas — full specification
| Property | Value | Basis |
|---|---|---|
| Specification | IS 5760 | Bureau of Indian Standards |
| Purity, welding grade | ≥99.99 % Ar | KIGL product specification. IS 5760 Table 1 sets impurity limits, not a minimum argon content. |
| Cylinder colour | Peacock blue | IS 4379 |
| Shielding gas standard | EN ISO 14175 | — |
| UN number | UN 1006 (compressed) | ADR 2025 |
| Proportion of atmosphere | 0.93 % | Composition of dry air, U.S. Standard Atmosphere (1976) |
| Chemical symbol | Ar | — |
| Grade supplied for welding | IS 5760 Grade 3 — welding and metallurgical operations | IS 5760 : 1998 cl 4 |
| Purity, high-purity grade | ≥99.999 % Ar, on request | KIGL product specification |
| Relative vapour density (air = 1) | ≈1.38 — heavier than air | Calculated from molar mass, NIST Chemistry WebBook |
| Supply form | Cylinders and cascades | — |
Documents
Argon gas — safety and technical documentation
Questions
Argon gas — frequently asked questions
Is argon gas flammable?
No. Argon is inert: it neither burns nor supports combustion, which is why it shields welds. The hazard is asphyxiation — at about 1.38 times the density of air it collects in pits and confined spaces and displaces oxygen with no smell or warning. Monitor oxygen before entry.
Why is argon better than nitrogen as a shielding gas?
Argon is a noble gas and genuinely inert under welding conditions. Nitrogen, despite being unreactive at room temperature, dissociates in the arc and can form nitrides in the weld metal, causing porosity and embrittlement in steels. Argon is also heavier than air, so it blankets the pool instead of drifting away.
Do I need pure argon or an argon mixture?
Pure argon for TIG on most materials, and for MIG on aluminium. For MIG on carbon and stainless steel an argon-CO₂ or argon-oxygen mixture usually gives better arc stability and penetration. State the material, thickness and process and KIGL will specify it rather than guess.
What purity do I need?
Welding grade at ≥99.99 % covers most fabrication. Reactive metals — titanium, zirconium — and analytical instrumentation need higher purity, because residual oxygen and moisture at even a few ppm cause discolouration or affect results. Aerospace and nuclear work often specifies higher grade for that reason.
Why does my TIG weld look grey or sooty?
Usually atmospheric contamination of the shield: gas flow too low, flow too high causing turbulence that pulls air in, a damaged gas lens, a leaking hose, or a draught across the work. Counter-intuitively, increasing flow is often the wrong fix — turbulence draws in more air than it excludes.
Does KIGL supply liquid argon?
Not currently. KIGL supplies liquid oxygen and liquid nitrogen; argon is cylinder and cascade supply. For a bulk argon requirement, contact KIGL and it will state plainly whether that requirement can be served.
Why is argon cylinder colour peacock blue?
IS 4379 colour coding. As always, confirm against the stamped markings and label rather than colour alone — customer-owned and traded cylinders in circulation do not always follow the code.
References
- Bureau of Indian Standards. (2021). Identification of the contents of industrial gas cylinders (IS 4379:2021, Second Revision).
- Linstrom, P. J., & Mallard, W. G. (Eds.). (n.d.). NIST Chemistry WebBook (NIST Standard Reference Database 69). National Institute of Standards and Technology.
- National Oceanic and Atmospheric Administration, National Aeronautics and Space Administration, & United States Air Force. (1976). U.S. Standard Atmosphere, 1976.
- The Kamrup Industrial Gases Limited. (2026). Company information and manufacturer's data [Company statement].
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Enquiries
Request a quotation for argon gas
State the gas or equipment, the quantity or capacity, and your location. KIGL will confirm the grade, the cylinder or plant size, and whether the location can be served from Noonmati, or through the agent network.